Question

the diagram on the right represents a pure substance in a container.
the model represents the arrangement of particles of this pure substance in the solid form.
the solid has a volume of 4 cm³.
thermal energy is added to this solid. before the solid changes phase, complete the sentence below that is describing what happens to particles, movement of the particles and the volume of the solid.
the particles begin to move choose your answer. and the attraction between the particles choose your answer
the particles will begin to choose your answer.
the volume will choose your answer.

Explanation:

1. For "The particles begin to move": When thermal energy is added to a solid, particles gain kinetic energy, so they move faster.
2. For "the attraction between the particles": As thermal energy increases, the kinetic energy of particles overcomes some of the intermolecular forces, so the attraction between particles decreases (but not enough to change phase yet).
3. For "The particles will begin to": With added energy, particles start to vibrate more vigorously (since in solid, they vibrate in fixed positions; more energy makes vibrations more intense).
4. For "The volume will": When a solid is heated before phase change, it expands slightly (thermal expansion), so the volume will increase a little (since particles move apart slightly due to increased vibration, taking up more space).

Answer:

• The particles begin to move: faster
• the attraction between the particles: decreases
• The particles will begin to: vibrate more vigorously
• The volume will: increase slightly